Drill assembly



Jan. 12, 1965 J. E. JORDON 3,164,962

DRILL ASSEMBLY Filed Nov. 2'7, 1962 INVENTOR: JOHN E.GORDON ATTORNEYUnited States Patent ()1 3,164,962 DRILL ASSEMBLY John E. Gordon, Gait,Ontario, Canada, assignor to Joy Manufacturing Company, Pittsburgh, Pa,a corporation of Pennsylvania Filed Nov. 27, 1962, Ser- No. 242,038

6 Claims. (Cl. 60-64) This invention relates to a drill assembly andmore particularly to a pressure fluid motor of the reciprocating pistontype such as those used for powering an air leg drill to produce boresin mineral strata preparatory to blasting as a part of a miningoperation.

The present invention provides a muffler, incorporated in the body ofsuch a pressure fluid, motor to' reduce exhaust noise therefrom. Maximumattenuation of exhaust noise from an air driven pressure fluid motor isaccom plishedwhen pulsation in the exhaust air impinging upon theatmosphere is reducedto a minimum. Of the many ways of doing this by farthe simplest is to provide an expansion chamber'of suflicient volumethat pulsations are absorbed within such chamber.

In the past such muffiers have been provided and have served the purposebut have not been satisfactory under all conditions of operation becausethey add substantially to the weight and size of the apparatus to whichthey are attached and as a further disadvantage have a tendency tofreeze up due to condensation and freezing of the mois' ture within theexhaust air. A partial freeze up, while not interrupting the operationof the motor, does reduce the efliciency of such motor operation byincreasing back pressure as is known. 1

The present invention contemplates provision of a mufller in the form ofa thin metal shroud surrounding a major portion of the pressure fluidmotor and radially spaced therefrom to provide sufficient enclosedvolume for the desired reduction in exhaust air pulsation. By this meanssuch volume is provided without materially increasing either the size orthe weight of the pressure fluid motor and heat, developed in the motorduring operation, conducted through the metal shroud prevents anysubstantial amount of freeze up. during operation and causes rapidmelting of any ice that may be formed whenever the operation is stoppedduring the normal drilling cycle.

It is therefore an object of this invention to provide a new andimproved pressure fluid operated motor.

It is a further object ofthis invention to provide a new and improvedpressure fluid operated motor having a mufller chamber for theattenuation of exhaust noise.

It is a'specific object of this invention to provide a new andimprovedair operated pressure fluid motor provided themotor and-radially spacedtherefrom toprovide suflicient enclosed volume for exhaust air expansionso that pulsations in the exhaust air are absorbed within the enclosedvolume resulting in attenuation of exhaust noise.

These and'other objects and advantages" of this invention will be morereadily apparent' on consideration of the following description anddrawings in which:

FIG. l-is atop plan view of a pressure fluid motor constructed accordingto the principles of this invention; 1 FIG. 2 is a sectional view takensubstantially on lines 22 ofF IG. l; a FIG; 3 is a sectional view takensubstantially onlines 3-3 of FIG. 2 g v FIG. 4' is an enlargedsectionalview taken substantially on line 4-4 of FIG. 1; I

FIG; 5 is an enlarged sectional on line 5 5"of FIG. 1. V 1

In FIG. 1 there is shown a pressure fluid motor genview takensubstantially erally indicated 'at 18, of the .typedes'cribed. andillustrated in US. Patent 2,922,396, comprising an elongated,hollow;

with a thin metallic shell surrounding a major portion of i 3,164,962Patented Jan. 12, 1965 ice formed, generally cylindrical body member 11having a forward end and a rearward end to the right and left,respectively, as viewed in FIGS. 1 and 2. A forward portion 12 of thebody member 11 has a smaller diameter than the main portion of the bodymember 11 and forms therewith a forwardly sloping oblique shoulder 13having, circumferentially spaced, raised ridge portions 14 upwardlyextending from the oblique shoulder 13 and having upper. surfacesgenerally parallel thereto. The body member 11 terminates rearwardly inan enlarged body portion 16 forming a peripheral shoulder 17 (see FIG.3) about the main body portion of the body member 11.

Rigidly secured to the rearward end of the body member 11 is a hollowformed end member 18 which is rigidly secured to a rearwardly extendinghandle member 19 partially shown in FIGS. 1 and 2. The body member 11has a stepped axial bore 21 therein having a cylinder portion22 and areduced diameter guide portion 23 slidably receiving different diameterportions of a stepped cylindrical piston member 24 reciprocable therein.An enlarged rearward portion 26 of the axial bore 21 suitably receives asuitable valve body 27 having a fluid actuated double valve 28 therein,and also suitably receives a rifle b'ar ratchet mechanism 29 designed toallow intermittent rotation of a helically splined rifle bar 31 in asingle direction as is known. Intermediate the ends of the cylinderportion 22 is an enlarged bore portion 32 communicating with theexterior of the body portion 11 by Way of exhaust ports or passageways33 to provide for the exhaust of compressed air from the cylinderportion 22 during end portions of the forward and backward stroke of thepiston 24 as is known.

A flexible fluid con-ducting line partially shown at 34 in FIG. 1communicates, by way of a suitable bore 35 and a manually operable valve36 through an annular passageway 37 in the end rnember18, throughsuitable bores in the ratchet mechanism 29 and suitable passageways inthe valve body 27, with the valve 28. The valve 28being axially movableis biased by fluid pressure into forward or rearward positions toestablish communication between the interior of the body 27 and suitablepassageways in the body member 11 so that alternatively the forward andrearward faces of the piston member 34 are acted upon by pressure fluidin a manner well known in the art to cause reciprocation of the piston24' within the cylinder portion 22. J r A formed hollow, thin metalliccasing or shell 40 radially outwardly spaced from the main body portionof the body member 11 is rigidly secured on the exterior peripheralsurface of the enlarged body portion 16 in fluid tight relationshiptherewith and extends forwardly therefrom to the ridges Men the obliqueshoulder 13. The shell 40 cooperates'with the body member 11 to form amuflier chamber 41 of suflicient volume to absorb pulsations in thecompressed air exhaust through the ports 33 as herein ways 46 areresiliently covered by athin, arcuate, flexible diaphragm member 43mounted .on the outer surfaces of the ridges-'14 and having an outerperiphery mating with the outer' surface of the semi-cylindrical portion40' of the shelldtll The diaphragm membe r 43 has an' inner peripherymating with the forward portion 12 to close x the passageways--46.portion ofjthe outersurface of the diaphragm member 43 inwardly adjacentits outer periphery and extending substantially the full length thereofis covered by an arcuate mounting plate 44 rigidly removably secured tothe ridges 14 as by cap screws 45 threadedly engaged with suitablethreaded bores in the ridges 14. The diaphragm member 43 is thus securedat circumferentially spaced points upon the outer surfaces of the ridges14 with its outer periphery abutting the forward edge of the shell 49.The portion of the diaphragm 43 outwardly adjacent its inner peripheryis free to be deformed outwardly and upwardly (see FIG. 5) by exhaustpressure as hereinafter more fully explained.

It is to be appreciated that the purposes of this invention can beaccomplished by a casing such as the shell 40 formed as an integral partof the housing 11 so that the muflier chamber 41 becomes a part of thehousing 11 similar to the water jacketing of an internal combustionengine.

In operating the fluid motor of this invention the fluid conducting line34 is connected to a source (not shown) of pressure fluid hereinafterreferred to as compressed air and through the communicating passageway35 compressed air is supplied to the interior of the valve 36. Suitableoperation of the valve 36 supplies compressed air through the annularpassageway 37 and the passageways through the ratchet mechanism 29 tothe interior of the valve body 27. At the beginning of such operationthe piston 24 will be in a rearward position adjacent the valve body 27and the valve 28 will be in a position to allow the passage of thecompressed air from the interior of the valve body 27 into the cylinderportion 22 rearwardly of the piston 24 applying force to the rearwardface thereof to move it forwardly as is known. As the piston movesforward it uncovers the enlarged bore portion 32 at the same time as thevalve 28 is suitably activated to cut olf the supply of compressed airfrom the rearward portion of the cylinder 22 while the compressed airwithin the rearward portion 22 is exhausted to the chamber 41 throughthe exhaust ports 33. Further action of the valve 28 connects theforward portion of the cylinder 22 with the source of compressed air andcauses the piston 24 to be moved backwardly so that the enlarged boreportion 32 is first covered and then uncovered at the time when thevalve 28 shuts off the flow of compressed air to the forward portion ofthe cylinder 22 and the compressed air in that portion of the cylinderis exhausted through the exhaust ports 33 into the chamber 41. Since theabove described action takes place very rapidly, air is exhaustedthrough the exhaust ports 33 in a series of sharp pulsations giving riseto the exhaust noise characteristic of such reciprocating type pressurefluid motors when being operated under normal conditions.

When air is exhausted from the exhaust ports 33 into the chamber 41 itdisplaces air already present in this chamber through the passageways 46formed by the ridges 14 and raising the lower edge of the'diaphragm 43as shown in FIG. 5 such displaced air passes out into the atmosphereforwardly over the small diameter 12 of. the

body member 11 to mingle with the surrounding air. The

volume of the chamber 41 is such that the pulsations, of the air exitingthrough the-exhaust ports 33 are almost completely absorbed therein sothat the air exiting under the diaphragm 43 is relatively free of thesharp pulsations which give rise to exhaust noise. The flexiblediaphragm 43 helps to damp the pulsations and is self adjustable to thevolume of exhaust air associated with different speeds of operation ofthe pressure fluid motor and further serves to prevent icing up of theexhaust orifice since any ice forming on the diaphragm 43 will be brokenup by its flexing action into discrete particles'which are swept out ofthe orifice formed by the diaphragm 43 and the reduced diameter portion12-of the body member 11.

. During continued operation of the fluid motor 10 cooling of the airdue to its expansion from its formerly compressed state can causecondensation and freezing of moisture from the air inside the chamber 41on the interior of the shell 40. However, 7, at the same time the bodymember 11 is being heated by the action of the compressed air within thecylinder 22 and as a result whenever the operation of the fluid motor isstopped the heat from the body member 11 conducted through the metalshell 40 melts such ice and thus prevents any undue accumulation of icewithin the chamber 41.

It is to be appreciated that since operation of this device necessitatesan operator grasping the handle 19 and positioned rearwardly of themotor 10, directing the exhaust forwardly over the reduced diameter ofthe motor 10 is advantageous in that dust is not blown into theoperators face and exhaust noise is further attenuated before reachinghis ears.

Further advantages resident in the fluid motor of this invention are theprovision of a sufliciently large chamber without significant increasein the size, weight or cost of the fluid motor 10 as compared to suchmotor without the noise reducing characteristics of the fluid motor ofthis invention.

A preferred embodiment of this invention having herein been describedand illustrated it is to be realized that variations therein may be madewithout departing from the broad spirit and scope of this invention.Accordingly it is respectfully requested that this invention beinterpreted as broadly as possible and be limited only by the prior art.

What I claim is:

l. A drill assembly comprising: a housing having a working chambertherein, a casing radially outwardly spaced from said working chamber toform a mufller chamber, at least one exhaust passageway communicatingbetween said Working chamber and said muffier chamber, said muiflerchamber having an exterior opening, said housing having on the outersurface thereof at least a pair of axially and laterally outwardlyextending portions abutting said casing to form an exhaust channeltherebetween, said exhaust channel communicating between the exterioropening and ambient atmosphere, means normally closing said exhaustchannel, said means being flexible to permit exhaust gases to flowoutwardly through said channels.

2. A drill assembly comprising: an elongated housing having a workingchamber therein, wall means radially outwardly spaced from said workingchamber to form a muflier chamber, at least one exhaust passagewaycommunicating between said working chamber and said muffler chamber,said muffler chamber having an exterior opening, said housing having onthe outer surface thereof at least a pair of axially and laterallyoutwardly extending portions abutting said wall means to form an exhaustchannel therebetween, said exhaust channel communicating between theexterior opening and ambient atmosphere, valve means normally closingsaid exhaust channel, and said valve means being flexible to permitexhaust gases to flow outwardly through said channel.

3. A drill assembly comprising: an elongated housing having a workingchamber therein, a handle disposed adjacent one end of said housing, anelongated casing radially outwardly spaced from said' working chamber toform a muflier chamber, one end of said casing being secured adjacentthe handle end of said housing, at least one exhaust passagewaycommunicating between said working chamber and said mufller chamber,said muffler chamber having an opening communicating with ambientatmosphere,;-said opening being disposed adjacent the other end ofsaidcasing, closure means normally closing said opening and beingflexible to permit exhaust gases to flow outwardly through said opening.

4. A drill assembly comprising: a fluid operated motor having anelongated housing; a handle disposed adjacent one end of said vhousing;said housing having first wall means forming a cylindrical workingchamber; second Wall means radially outwardly spaced from said workingchamber to form a mufiler chamber; at least a portion of said first wallmeans between said chambers being formed of material which readilyconducts heat; said second wall means having a first end and a secondend; the first end of said second wall means being secured to the handleend of said housing in fluid tight relationship therewith; at least oneexhaustpassageway communicating between said working chamber and saidmufller chamber; said mufiler chamber having an exterior opening; aplurality of axially extended, circumferentially spaced, raised ridgeportions of said housing supporting the second end of said second wallmeans; said raised ridge portions forming a plurality of exhaustchannels communicating from the exterior opening to the ambientatmosphere; said exhaust channels being adjacent the secend end of saidsecond wall means axially spaced from the handle end of said housing sothat exhaust fluid is directed away from the handle end of said housing;valve means normally closing said exhaust channels; and said valve meansbeing flexible to permit exhaust gases to flow outwardly through saidchannels.

5. A drill assembly comprising:- a fluid operated'motor having anelongated housing; a handle disposed adjacent one end of said housing;said housing having first wall means forming a cylindrical workingchamber; said working chamber having an output member reciprocatinglymovable in a path therein; second wall means radially outwardlyspacedfrom said working chamber to form a muffler chamber; at least aportion of said first wall means between thesaid chambers being formedof material which readily conducts heat; said second Wall means having afirst end and a second end; the first end of said second wall meansbeing secured to the handle end of said housing in fluid tightrelationship therewith; at least one exhaust passageway communicatingbetween said a Working chamber and said miufiler chamber; the motion ofsaid output member controlling intermittent fluid flow through saidexhaust passageway, and said mufiler chamher having an exterior,opening; a plurality of axially extended, circumferentially spaced,raised ridge portions of said housing supporting the second end of saidsecond wall means; said raised ridge portions forming a plurality ofexhaust channels communicating from the exterior opening to the ambientatmosphere; said exhaust channels being adjacent the second end of saidsecond wall means axially spaced from the handle end of said housend ofsaid housing; valve means normally closing said exhaust channels; andsaid valve means being flexible to permit exhaust gases to flowoutwardly through said channels. v

6. A drill assembly comprising: a fluid operated motor having anelongated housing; a handle disposed adjacent one end of said housing;said housing having first wall means forming an elongated cylindricalworking chamher; said working chamber having an output memberlongitudinally reciprocatingly movable therein; second wall meansradially outwardly spaced from said working chamber to form a mufflerchamber; at least a portion of said first Wall means between the saidchambers being formed or" material which readily conducts heat; saidsecond Wall means having a first end and a second end; the first end ofsaid second wall means being secured to the handle end of said housingin fluidtight relationship therewith; a plurality of exhaust passagewayscommunicating between said working chamber and said niuiller chamber;the motion of said output member controlling intermittent fluid flowthrough said exhaust passageways;-said mufiler chamber having anexterior opening; a plurality of axially extended, circumferentiallyspaced, raised ridge portions of said housing supporting the second endof said second wall means; said raised ridge portions forming aplurality of exhaust channels communicating from the exterior opening tothe ambient atmosphere; said exhaust channels being adjacent the sec 0ndend of said second wall means axially spaced from ing so that exhaustfiuid is directed away from the handle the handle end of said housing sothat exhaust fluid is directed away from; the handle end of saidhousing; valve means normally closing said exhaust channels; and saidvalve means being flexible to permit exhaust gases to flow outwardlythrough said channels.

Sweden May 23, 1933

1. A DRILL ASSEMBLY COMPRISING: A HOUSING HAVING A WORKING CHAMBERTHEREIN, A CASING RADIALLY OUTWARDLY SPACED FROM SAID WORKING CHAMBER TOFORM A MUFFLER CHAMBER, AT LEAST ONE EXHAUST PASSAGEWAY COMMUNICATINGBETWEEN SAID WORKING CHAMBER AND SAID MUFFLER CHAMBER, SAID MUFFLERCHAMBER HAVING AN EXTERIOR OPENING, SAID HOUSING HAVING ON THE OUTERSURFACE THEREOF AT LEAST A PAIR OF AXIALLY AND LATERALLY OUTWARDLYEXTENDING PORTIONS ABUTTING SAID CASING TO FORM AN EXHAUST CHANNELTHEREBETWEEN, SAID EXHAUST CHANNEL COMMUNICATING BETWEEN THE EXTERIOROPENING AND AMBIENT ATMOSPHERE, MEANS NORMALLY CLOSING SAID EXHAUSTCHANNEL, SAID MEANS BEING FLEXIBLE TO PERMIT GASES TO FLOW OUTWARDLYTHROUGH SAID CHANNELS.